Bell's Palsy and Bell's Phenomenon

Abstract

Bell (1774 to 1842) should have described the syndrome and the phenomenon that now bear his name.1-4 He was trained in anatomy, surgery, and art; he made a detailed study of facial expression; he discovered the separate actions of the trigeminal and facial nerves; and because of these interests, he saw an unusual number of patients with facial paralysis in his clinical practice.Early in the course of his medical education in Edinburgh, Charles Bell received instruction from his older brother John, one of the foremost anatomists and surgeons of the time. His contribution to John's textbook of anatomy5 was one of the first of Charles' numerous publications, which included textbooks and atlases of neuroanatomy and surgery. A gifted artist, he illustrated many of these works himself.Bell's training in anatomy and his interest in art led him to a comprehensive study of facial expression, first published in 1806.6The following year, Bell began his classical studies of nerve function, and became the first to distinguish between sensory and mo¬ tor nerves.7 Though he misinterpreted his observations initially,3·8 Bell's basic discov¬ ery was verified and expanded by several other investigators, including François Magendie.9·10 The fact that sensory nerves enter the spinal cord by the posterior roots and motor nerves leave it by the anterior roots is now known as the Bell-Magendie law.11Like most anatomists of his time, Bell recognized only nine sets of cranial nerves.312·13 The fifth pair were the trigem¬ inal nerves, as in the present nomencla-ture, but the seventh nerve was divided into a portio dura (facial nerve) and a portio mollis (acoustic nerve). As his research into the anatomy and physiology of the nerves progressed, Bell established that the trigeminal and facial nerves have separate functions.1417 Bell proceeded to introduce a new method of classifying the nerves accord¬ ing to their function as well as their form.Thus he grouped the trigeminal nerve with the spinal nerves, since it subserves both sensation and motion and since it has a ganglion on its sensory root. In contrast, he classified the facial nerve (respiratory nerve of the face) with other nerves that he thought were concerned with respiration. These included the long thoracic Cexternal respiratory) nerve, now known as the nerve of Bell.

Reciprocal Reflex Activity in Ocular Muscles:Implications in Spontaneous Blinking and Bell’s Phenomenon

“…overactivation has also been obtained during spontaneous blinking {Bjork, 1954a) and glabellar tapping, although we have never been able to find it during electrically induced blink reflex. This reflex Bell phenomenon could confirm Bell's observa tion in his classic description ( Wilkins and Brody, 1969), later corroborated by Bender (1960Bender ( , 1969, of a brief, upward movement of the eyeballs in spontaneous blinking. Its sys tematic absence in the electrical blink reflex does not have an easy explanation; it is possible that the unilateral stimulus used was not appro priate or sufficient to induce this vertical ocular movement.…”

Sir Charles Bell (1774−1842): contributions to neuro‐ophthalmology

“…Bell pursued the matter further and observed the same occurrence in normal individuals. The palpebraloculogyric reflex, which is more noticeable when eyelid closure is incomplete, is now known as Bell's phenomenon (Wilkins & Brody 1969).…”

The Eyelid and Its Contribution to Eye Movements

“…Long-lasting eye closure causes an upward eye drift known as Bell's phenomenon [58,59]; short eye closure with blinks induces distinctly different eye movements in humans ( fig. 1) [2,42,45,47,59,60].…”